Hoenn is mine. I am super biased when it comes to regions, I just think Hoenn is the best in everything and it is the region I spent the most time in as a child (around 500 hours between Sapphire and Emerald). Pheobe is my favorite of any elite four member, probably Wikstrom is my second favorite. My second favorite is probably Alola, I like that you can pick the order you challenge and I really like the flying type member. Sadly, I never completed a Sinnoh game because it is the only time in my life I didn't play current gen Pokemon and the copy of Pearl I managed to find for 40 dollars is busted. I also tried playing through Platinum on Desmume but it also bugged and I lost my progress after one gym. I have accepted that I will never play through original Sinnoh past the first gym but I hear good things about the Elite Four and champion.